A satellite data unit (SDU) is a component of an aircraft's satellite communication system and enables both air-to-ground and ground-to-air communication via a satellite network. In particular, a typical SDU is designed to support data channels for packet data services (also referred to as “data-link” services) and designed to support voice channels for voice services. An SDU designed in this manner can engage in both voice and data communication with at least one satellite of the satellite network. Voice communication, for instance, can involve an audio message sent from a pilot or other individual on the aircraft to an individual at a ground station (e.g., an air traffic controller), or vice versa. Data communication, which can include text messages, location data, speed data, altitude data, and/or other information associated with (or not associated with) the aircraft, can be used in addition to voice communication. In some scenarios, data communication can be used in lieu of voice communication, such as when the aircraft is too far from an air traffic control tower or other ground station.
Existing satellite communication systems include multiple SDUs, where each SDU is configured to engage in communication (e.g., voice, data, or other) with a satellite network. Typically, due to concerns of radio frequency interference between two or more SDUs that are engaging in communications with the satellite network, only one SDU is allowed to be active and transmitting radio frequency signals at a given time. To facilitate this, existing methods involve configuring the SDUs of an aircraft to each have local program logic that enables the SDUs to communicate with each other, to determine when to switch which SDU is active, and to determine which one of the SDUs to make active.
However, these existing methods can negatively impact cost and complexity. For example, SDUs of an aircraft are often provided by different suppliers, and thus, the different SDUs are required to be configured to integrate with each other and with other components of the satellite communication system. This requirement increases the cost of each SDU and of the satellite communication system. Furthermore, configuring each SDU to have the program logic described above increases the complexity of the satellite communication system.
What is needed are systems and methods for controlling which SDU to make active that are efficient, less expensive, and less complex.